1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Flash memory access on SA11x0 based devices
4 *
5 * (C) 2000 Nicolas Pitre <nico@fluxnic.net>
6 */
7 #include <linux/module.h>
8 #include <linux/types.h>
9 #include <linux/ioport.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/errno.h>
13 #include <linux/slab.h>
14 #include <linux/platform_device.h>
15 #include <linux/err.h>
16 #include <linux/io.h>
17
18 #include <linux/mtd/mtd.h>
19 #include <linux/mtd/map.h>
20 #include <linux/mtd/partitions.h>
21 #include <linux/mtd/concat.h>
22
23 #include <mach/hardware.h>
24 #include <linux/sizes.h>
25 #include <asm/mach/flash.h>
26
27 struct sa_subdev_info {
28 char name[16];
29 struct map_info map;
30 struct mtd_info *mtd;
31 struct flash_platform_data *plat;
32 };
33
34 struct sa_info {
35 struct mtd_info *mtd;
36 int num_subdev;
37 struct sa_subdev_info subdev[];
38 };
39
40 static DEFINE_SPINLOCK(sa1100_vpp_lock);
41 static int sa1100_vpp_refcnt;
sa1100_set_vpp(struct map_info * map,int on)42 static void sa1100_set_vpp(struct map_info *map, int on)
43 {
44 struct sa_subdev_info *subdev = container_of(map, struct sa_subdev_info, map);
45 unsigned long flags;
46
47 spin_lock_irqsave(&sa1100_vpp_lock, flags);
48 if (on) {
49 if (++sa1100_vpp_refcnt == 1) /* first nested 'on' */
50 subdev->plat->set_vpp(1);
51 } else {
52 if (--sa1100_vpp_refcnt == 0) /* last nested 'off' */
53 subdev->plat->set_vpp(0);
54 }
55 spin_unlock_irqrestore(&sa1100_vpp_lock, flags);
56 }
57
sa1100_destroy_subdev(struct sa_subdev_info * subdev)58 static void sa1100_destroy_subdev(struct sa_subdev_info *subdev)
59 {
60 if (subdev->mtd)
61 map_destroy(subdev->mtd);
62 if (subdev->map.virt)
63 iounmap(subdev->map.virt);
64 release_mem_region(subdev->map.phys, subdev->map.size);
65 }
66
sa1100_probe_subdev(struct sa_subdev_info * subdev,struct resource * res)67 static int sa1100_probe_subdev(struct sa_subdev_info *subdev, struct resource *res)
68 {
69 unsigned long phys;
70 unsigned int size;
71 int ret;
72
73 phys = res->start;
74 size = res->end - phys + 1;
75
76 /*
77 * Retrieve the bankwidth from the MSC registers.
78 * We currently only implement CS0 and CS1 here.
79 */
80 switch (phys) {
81 default:
82 printk(KERN_WARNING "SA1100 flash: unknown base address "
83 "0x%08lx, assuming CS0\n", phys);
84 fallthrough;
85 case SA1100_CS0_PHYS:
86 subdev->map.bankwidth = (MSC0 & MSC_RBW) ? 2 : 4;
87 break;
88
89 case SA1100_CS1_PHYS:
90 subdev->map.bankwidth = ((MSC0 >> 16) & MSC_RBW) ? 2 : 4;
91 break;
92 }
93
94 if (!request_mem_region(phys, size, subdev->name)) {
95 ret = -EBUSY;
96 goto out;
97 }
98
99 if (subdev->plat->set_vpp)
100 subdev->map.set_vpp = sa1100_set_vpp;
101
102 subdev->map.phys = phys;
103 subdev->map.size = size;
104 subdev->map.virt = ioremap(phys, size);
105 if (!subdev->map.virt) {
106 ret = -ENOMEM;
107 goto err;
108 }
109
110 simple_map_init(&subdev->map);
111
112 /*
113 * Now let's probe for the actual flash. Do it here since
114 * specific machine settings might have been set above.
115 */
116 subdev->mtd = do_map_probe(subdev->plat->map_name, &subdev->map);
117 if (subdev->mtd == NULL) {
118 ret = -ENXIO;
119 goto err;
120 }
121
122 printk(KERN_INFO "SA1100 flash: CFI device at 0x%08lx, %uMiB, %d-bit\n",
123 phys, (unsigned)(subdev->mtd->size >> 20),
124 subdev->map.bankwidth * 8);
125
126 return 0;
127
128 err:
129 sa1100_destroy_subdev(subdev);
130 out:
131 return ret;
132 }
133
sa1100_destroy(struct sa_info * info,struct flash_platform_data * plat)134 static void sa1100_destroy(struct sa_info *info, struct flash_platform_data *plat)
135 {
136 int i;
137
138 if (info->mtd) {
139 mtd_device_unregister(info->mtd);
140 if (info->mtd != info->subdev[0].mtd)
141 mtd_concat_destroy(info->mtd);
142 }
143
144 for (i = info->num_subdev - 1; i >= 0; i--)
145 sa1100_destroy_subdev(&info->subdev[i]);
146 kfree(info);
147
148 if (plat->exit)
149 plat->exit();
150 }
151
sa1100_setup_mtd(struct platform_device * pdev,struct flash_platform_data * plat)152 static struct sa_info *sa1100_setup_mtd(struct platform_device *pdev,
153 struct flash_platform_data *plat)
154 {
155 struct sa_info *info;
156 int nr, size, i, ret = 0;
157
158 /*
159 * Count number of devices.
160 */
161 for (nr = 0; ; nr++)
162 if (!platform_get_resource(pdev, IORESOURCE_MEM, nr))
163 break;
164
165 if (nr == 0) {
166 ret = -ENODEV;
167 goto out;
168 }
169
170 size = sizeof(struct sa_info) + sizeof(struct sa_subdev_info) * nr;
171
172 /*
173 * Allocate the map_info structs in one go.
174 */
175 info = kzalloc(size, GFP_KERNEL);
176 if (!info) {
177 ret = -ENOMEM;
178 goto out;
179 }
180
181 if (plat->init) {
182 ret = plat->init();
183 if (ret)
184 goto err;
185 }
186
187 /*
188 * Claim and then map the memory regions.
189 */
190 for (i = 0; i < nr; i++) {
191 struct sa_subdev_info *subdev = &info->subdev[i];
192 struct resource *res;
193
194 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
195 if (!res)
196 break;
197
198 subdev->map.name = subdev->name;
199 sprintf(subdev->name, "%s-%d", plat->name, i);
200 subdev->plat = plat;
201
202 ret = sa1100_probe_subdev(subdev, res);
203 if (ret)
204 break;
205 }
206
207 info->num_subdev = i;
208
209 /*
210 * ENXIO is special. It means we didn't find a chip when we probed.
211 */
212 if (ret != 0 && !(ret == -ENXIO && info->num_subdev > 0))
213 goto err;
214
215 /*
216 * If we found one device, don't bother with concat support. If
217 * we found multiple devices, use concat if we have it available,
218 * otherwise fail. Either way, it'll be called "sa1100".
219 */
220 if (info->num_subdev == 1) {
221 strcpy(info->subdev[0].name, plat->name);
222 info->mtd = info->subdev[0].mtd;
223 ret = 0;
224 } else if (info->num_subdev > 1) {
225 struct mtd_info **cdev;
226
227 cdev = kmalloc_array(nr, sizeof(*cdev), GFP_KERNEL);
228 if (!cdev) {
229 ret = -ENOMEM;
230 goto err;
231 }
232
233 /*
234 * We detected multiple devices. Concatenate them together.
235 */
236 for (i = 0; i < info->num_subdev; i++)
237 cdev[i] = info->subdev[i].mtd;
238
239 info->mtd = mtd_concat_create(cdev, info->num_subdev,
240 plat->name);
241 kfree(cdev);
242 if (info->mtd == NULL) {
243 ret = -ENXIO;
244 goto err;
245 }
246 }
247 info->mtd->dev.parent = &pdev->dev;
248
249 if (ret == 0)
250 return info;
251
252 err:
253 sa1100_destroy(info, plat);
254 out:
255 return ERR_PTR(ret);
256 }
257
258 static const char * const part_probes[] = { "cmdlinepart", "RedBoot", NULL };
259
sa1100_mtd_probe(struct platform_device * pdev)260 static int sa1100_mtd_probe(struct platform_device *pdev)
261 {
262 struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
263 struct sa_info *info;
264 int err;
265
266 if (!plat)
267 return -ENODEV;
268
269 info = sa1100_setup_mtd(pdev, plat);
270 if (IS_ERR(info)) {
271 err = PTR_ERR(info);
272 goto out;
273 }
274
275 /*
276 * Partition selection stuff.
277 */
278 mtd_device_parse_register(info->mtd, part_probes, NULL, plat->parts,
279 plat->nr_parts);
280
281 platform_set_drvdata(pdev, info);
282 err = 0;
283
284 out:
285 return err;
286 }
287
sa1100_mtd_remove(struct platform_device * pdev)288 static int sa1100_mtd_remove(struct platform_device *pdev)
289 {
290 struct sa_info *info = platform_get_drvdata(pdev);
291 struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
292
293 sa1100_destroy(info, plat);
294
295 return 0;
296 }
297
298 static struct platform_driver sa1100_mtd_driver = {
299 .probe = sa1100_mtd_probe,
300 .remove = sa1100_mtd_remove,
301 .driver = {
302 .name = "sa1100-mtd",
303 },
304 };
305
306 module_platform_driver(sa1100_mtd_driver);
307
308 MODULE_AUTHOR("Nicolas Pitre");
309 MODULE_DESCRIPTION("SA1100 CFI map driver");
310 MODULE_LICENSE("GPL");
311 MODULE_ALIAS("platform:sa1100-mtd");
312